Two thirds of North Americans sleep on their sides. While this position is very comfortable and is often recommended by medical practitioners, it causes bending of the spinal cord potentially leading to strain on the muscles, ligaments, bones, and joints; compression of the internal organs; decrease in blood flow; and irritation of the nerves. Also, resting on the side results in a prolonged contact of the thighs, knees, and calves potentially leading to obstruction of blood flow, painful cramps, and bruising.
These problems are exacerbated in people with medical problems, such as back pains due to trauma, various knee conditions, and arthritis. These problems are also exacerbated in obese people and pregnant women, who due to their large weight experience additional pressure on the lumbar spine, sacroiliac joint, sciatic nerve, and lower extremities and often have lower back pains, edema of legs, and varicose veins.
Also, certain medical conditions (and pregnancy is one of them) require everyday prolonged rest lying down, which in turn means prolonged contact of the legs and prolonged bending of the spine, potentially leading to all of the above described problems.
To alleviate the discomfort caused by these problems and to promote restful sleep, doctors have long recommended that patients place a pillow between their legs when sleeping on the side. Between-the-legs pillows facilitate the proper alignment of the spine, thighs, and calves relieving pain and discomfort, preventing gout, and improving general health. These pillows also relieve physical stress and strain after exercise.
Since conventional pillows are not shaped properly and are easily displaced during sleep, several specifically designed support pillows have been proposed in the prior art.
U.S. Pat. No. 4,584,730, to E. Rajan, shows a disc-shaped flat pillow with two basically parallel planar surfaces. This pillow has several protrusions used as means to space the pillow apart from the mattress. A person lying on his or her side can have one leg resting on the mattress (underneath the pillow) and the other leg resting on the upper surface of the pillow. This pillow also has protrusions confining the pelvis of the user. While this pillow separates the legs and aligns the spine, it is flat, does not conform to the shape of the human legs and, therefore, does not provide the maximum comfort to the user. Also, confining the pelvis is important only in special circumstances such as for handicapped children with brain disorders who have characteristic patterns of movement and resting positions gradually damaging their ability to sit. Pelvic restriction is unnecessary and uncomfortable in regular situations, because it restricts mobility and causes sweating and irritation of the pelvis. Overall, this pillow is very large, bulky and intended to restrict the movement of the user. Therefore, it is not convenient to use in casual situations.
U.S. Pat. No. 4,736,477, to G. Moore, shows a flat pillow for positioning between the person's knees, when he or she is required to recline to one side for a long time. The pillow is generally rectangular in planar form, and includes a series of notches permitting the pillow to deflect in a manner consistent with the movement of the knee. The pillow is fasten to the knee by a plurality of straps with hookable fasteners. While this pillow provides a cushioning and support for user's upper leg and helps to maintain the proper alignment of the spine, it has two limitations. First, this pillow is flat, does not conform to the shape of the human legs and, therefore, does not provide the maximum comfort and may even cause obstruction of blood flow in the legs. Second, this pillow contains cushioning for the knees which is undesirable because the knees are usually bony even in very obese people, the blood vessels are positioned close to the surface and are easily obstructed. Also, the back side of the knees contains sweat glands and cushioning will interfere with evaporation of the sweat, causing discomfort and irritation.
U.S. Pat. No. 5,117,522, to P. Everett, shows a flat rectangular pillow for placing between the person's legs while this person is lying on his or her back. The pillow is retained in its place between the legs by the shape (I-beam intersection) and by the flexible straps attached to the pillow for extension around the person's legs. The pillow has a transverse triangular notch that forms a hinge connection between two sections of the pillow allowing the person to comfortably bend his or her legs. Similar to the pillows described in the U.S. Pat. Nos. 4,584,730 and 4,736,477, this pillow is flat and contains cushioning between the knees, which makes it less comfortable for the user. Also, the straps attaching the pillow to the legs extend around both legs. This is a good solution in the case of a person resting on his or her back. However, if the pillow is to be used for resting on the side, the straps fitting underneath the legs may cause discomfort, bruising and irritation.
U.S. Pat. No. 5,664,271, to J. M. Bellavance, a pillow assembly for cushioning the body of a pregnant or obese person while this person is lying on her or his side and includes an abdominal pillow adapted to partially underlie the person's abdomen and a leg pillow adapted to be positioned between the person's legs. The leg pillow can be made as a single leg pillow extending from the person's upper thigh to the lower calf or as an assembly of two separate pillows (thigh and calf) interconnected by flap structures. The single leg pillow has the same basic limitations as the pillows described in the above U.S. Pat. Nos. 4,584,730, 4,736,477 and 5,117,522. The assembly of the two pillows is superior to the pillows described in these above patents in that it does not have the knee cushioning and is better fitted to the shape of the human legs. However, it is still not optimal for the user's comfort because it does not account for the natural asymmetry of the human thighs and calves. Also, the two flap structures connecting the pillows are positioned and attached to each other between the user's knees, which may cause irritation and bruising.
In conclusion, the prior art inventions provide a partial solution to the problems caused by an incorrect positioning of the body during sleeping or resting on one's side. However, all these inventions possess a number of limitations. These limitations are conveniently solved by the present invention, which in the course of extensive experimentation was found to possess more comfortable features and to greatly contribute to the health and well being of its users.